The rat has been a valuable model for many applications, including, but not limited to, applications in drug discovery. The usefulness of the rat has been mitigated somewhat by difficulty in obtaining genetically modified rats, in particular, in developing methods for genetically modifying rats, and generating useful rat cells that can be used in genetic modification protocols, including but not limited to protocols that result in germline transmission of a genetic modification in a rat genome.
There is a need in the art for rat cells (e.g., embryonic stem cells) that can be genetically modified such that the genetic modification can be transmitted through the germline. There is a need in the art for improved frequency of germline transmission of genetic modifications in rats.
There is a need in the art for donor rat pluripotent, totipotent, and/or ES cells from various strains of rat that are capable of generating F0, or wholly donor cell-derived, F0 rats. There is a need in the art for donor rat pluripotent, totipotent, and/or ES cells that are capable of generating rats that comprise a germline genetic modification.